Dr Sarah Brewer, an award-winning writer and the author of 50 popular self-help books, also outlined the benefits of CBD oil.

She said: “CBD oil has a lifting and relaxing effect on mood with none of the adverse psychoactive effects associated with marijuana.

“It acts via the body’s own endocannabinoid system to promote feelings of wellbeing.

“It’s a great choice if youâ€™re finding it difficult to relax as it’s not habit-forming,” she added, noting that the oil is ‘particularly helpful for reducing anxiety, promoting relaxation and restful sleep’.

CBD oil went on sale at Holland & Barrett at the start of the year and the high street retailer boasted a 37 per cent increase in sales in the space of four weeks.

It is advised that people discuss CBD oil with their doctor before using it.